Buggy code:
public abstract class AbstractKernelServicesImpl extends ModelTestKernelServicesImpl < KernelServices > implements KernelServices { static final AtomicInteger counter = new AtomicInteger ( ) ; protected AbstractKernelServicesImpl ( ServiceContainer container , ModelTestModelControllerService controllerService , StringConfigurationPersister persister , ManagementResourceRegistration rootRegistration , OperationValidator operationValidator , ModelVersion legacyModelVersion , boolean successfulBoot , Throwable bootError , ExtensionRegistry extensionRegistry ) { } public static AbstractKernelServicesImpl create ( ProcessType processType , RunningModeControl runningModeControl , boolean validateOperations , List < ModelNode > bootOperations , ModelTestParser testParser , ModelVersion legacyModelVersion , TestModelType type , ModelInitializer modelInitializer , ExtensionRegistry extensionRegistry , List < String > contentRepositoryHashes ) throws Exception { ServiceContainer container = Factory . create ( ( "test" + ( AbstractKernelServicesImpl . counter . incrementAndGet ( ) ) ) ) ; ServiceTarget target = container . subTarget ( ) ; File repositoryFile = new File ( "target//deployment-repository" ) ; if ( contentRepositoryHashes != null ) { AbstractKernelServicesImpl . deleteFile ( repositoryFile ) ; repositoryFile . mkdir ( ) ; for ( String hash : contentRepositoryHashes ) { File file = new File ( repositoryFile , hash . substring ( 0 , 2 ) ) ; file . mkdir ( ) ; file = new File ( file , hash . substring ( 2 , hash . length ( ) ) ) ; file . mkdir ( ) ; file = new File ( file , "content" ) ; file . createNewFile ( ) ; } } ContentRepository . Factory . addService ( target , repositoryFile ) ; <START_BUG> StringConfigurationPersister persister = new StringConfigurationPersister ( bootOperations , testParser ) ; <END_BUG> TestModelControllerFactory testModelControllerFactory = AbstractKernelServicesImpl . StandardTestModelControllerServiceFactory . INSTANCE ; if ( legacyModelVersion != null ) { ServiceLoader < TestModelControllerFactory > factoryLoader = ServiceLoader . load ( TestModelControllerFactory . class , AbstractKernelServicesImpl . class . getClassLoader ( ) ) ; for ( TestModelControllerFactory factory : factoryLoader ) { testModelControllerFactory = factory ; break ; } } ModelTestModelControllerService svc = testModelControllerFactory . create ( processType , runningModeControl , persister , validateOperations , type , modelInitializer , extensionRegistry ) ; ServiceBuilder < ModelController > builder = target . addService ( JBOSS_SERVER_CONTROLLER , svc ) ; builder . addDependency ( SERVICE_NAME , ContentRepository . class , testModelControllerFactory . getContentRepositoryInjector ( svc ) ) ; builder . install ( ) ; svc . waitForSetup ( ) ; AbstractKernelServicesImpl kernelServices = ( legacyModelVersion == null ) ? new MainKernelServicesImpl ( container , svc , persister , svc . getRootRegistration ( ) , new OperationValidator ( svc . getRootRegistration ( ) ) , legacyModelVersion , svc . isSuccessfulBoot ( ) , svc . getBootError ( ) , extensionRegistry ) : new LegacyKernelServicesImpl ( container , svc , persister , svc . getRootRegistration ( ) , new OperationValidator ( svc . getRootRegistration ( ) ) , legacyModelVersion , svc . isSuccessfulBoot ( ) , svc . getBootError ( ) , extensionRegistry , ContentRepository . Factory . create ( repositoryFile ) ) ; return kernelServices ; } private static void deleteFile ( File file ) { } public abstract TransformedOperation transformOperation ( ModelVersion modelVersion , ModelNode operation ) throws OperationFailedException { } public abstract ModelNode readTransformedModel ( ModelVersion modelVersion ) { } public abstract ModelNode callReadMasterDomainModelHandler ( ModelVersion modelVersion ) { } public abstract ModelNode executeOperation ( final ModelVersion modelVersion , final TransformedOperation op ) { } protected void addLegacyKernelService ( ModelVersion modelVersion , KernelServices legacyServices ) { } private static class StandardTestModelControllerServiceFactory implements TestModelControllerFactory { static final TestModelControllerFactory INSTANCE = new AbstractKernelServicesImpl . StandardTestModelControllerServiceFactory ( ) ; @ Override public ModelTestModelControllerService create ( ProcessType processType , RunningModeControl runningModeControl , StringConfigurationPersister persister , boolean validateOperations , TestModelType type , ModelInitializer modelInitializer , ExtensionRegistry extensionRegistry ) { } @ Override public InjectedValue < ContentRepository > getContentRepositoryInjector ( ModelTestModelControllerService service ) { } } }

Fix:
StringConfigurationPersister persister = new StringConfigurationPersister ( bootOperations , testParser , true ) ;